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Biomedical subjects

T Shibuya

Publications and source records attributed to T Shibuya.

At least 307 records · Page 17Linked to original sources
PubMed1988

Expression of the granulocyte/macrophage colony-stimulating factor gene in leukemic blast cells from patients with acute non-lymphocytic leukemia.

Since granulocyte/macrophage colony-stimulating factor (GM-CSF) has been reported to stimulate the proliferation of clonogenic leukemia cells from patients with acute non-lymphocytic leukemia in vitro, the expression of the GM-CSF gene in primary human leukemic blast cells was studied. T-cell-depleted mononuclear cells in freshly drawn peripheral blood from patients with acute non-lymphocytic leukemia (ANLL) were subjected to the study. The expression of the GM-CSF gene was detected by Northern blotting analysis using [32P]GM-CSF as a probe. The GM-CSF gene was expressed in two out of five cases examined. In both of the patients who showed GM-CSF expression, remission could not be achieved.

Acute Disease↗
PubMed1988

[Clinical study on the effect of natural alpha-interferon (HLBI) in the treatment of adult T-cell leukemia].

The phase II trial of natural interferon-alpha (HLBI) in treatment of adult T-cell leukemia was carried out as a cooperative study. Of the 24 cases which could be evaluated, 3 cases in crisis type and 5 cases in chronic type with lymphadenopathy and/or skin infiltration achieved PR, giving a response rate of 33.3%. The anti-tumor effect of HLBI for skin lesion could be assessed in 16 cases with skin infiltration, giving a response rate of 50.0% (5 CR and 3 PR) and demonstrating a high efficacy. Of the 31 eligible patients, side effects were recognised in 27 (87.1%). Major subjective and objective symptoms were fever (38.7%), fatigue (25.8%), anorexia (12.9%) and nausea (12.9%), and leukopenia (22.6%), granulocytopenia (38.7%), thrombocytopenia (38.7), elevation of GPT (12.9%) and GOT (12.9%) were observed.

Adult↗
PubMed1988

A possible mechanism on the potentiating vascular effect of coadministration of ifenprodil tartrate and calcium hopantenate: a study in the internal carotid artery.

Recently, it has been proposed that the combined administration of ifenprodil tartrate and calcium hopantenate might produce a beneficial synergistic effect in the treatment of cerebrovascular diseases. To further examine this clinical phenomena, the blood flow in the internal carotid arteries of the rat and the isometric tension of canine internal carotid arteries were measured with a transit-time ultrasonic volume flowmeter and a force transducer, respectively. Ifenprodil tartrate produced a sustained increase in the internal carotid arterial blood flow of rats, while calcium hopantenate had no effect. However, the increase in the internal carotid arterial blood flow induced by ifenprodil tartrate was significantly enhanced by calcium hopantenate. Ifenprodil tartrate caused a dose-related relaxation of K+-induced contractions in the isolated canine internal carotid arteries, while calcium hopantenate had no effect. The dose-response curve of ifenprodil tartrate was shifted to the left by pre-incubation in calcium hopantenate. Ifenprodil tartrate inhibited the K+-induced Ca2+ uptake in the canine internal carotid arteries, and the inhibition induced by ifenprodil tartrate was significantly enhanced by calcium hopantenate. These results suggest that the observed enhancement by calcium hopantenate of the ifenprodil tartrate effect on the internal carotid arterial blood flow was due to increased vascular myorelaxation resulting from the influence of calcium hopantenate on the Ca2+ movement.

Animals↗
PubMed1988

A possible mechanism on the potentiated vascular effect of coadministration of ifenprodil tartrate and calcium hopantenate: a study in the basilar and vertebral arteries.

In our earlier report [Shibuya et al. in press], we demonstrated the partial mechanism of the synergism between ifenprodil tartrate and calcium hopantenate on cardiovascular diseases. The mechanisms of the synergistic effects in the basilar and vertebral arteries were further studied in this paper using our described methods. Ifenprodil tartrate produced a sustained increase in the vertebral arterial blood flow of rats, while calcium hopantenate. Ifenprodil tartrate caused dose-related relaxation of K+-induced contractions in by ifenprodil tartrate was significantly enhanced by the coadministration of calcium hopantenate. Ifenprodil tartrate caused dose-related relaxation of K+-induced contractions in isolated canine basilar arteries, while calcium hopantenate had no effect. The dose-relaxation curve of ifenprodil tartrate was shifted to the left by pre-incubation in calcium hopantenate. In K+-depolarized basilar arteries, ifenprodil competitively antagonized the response to Ca2+, and this was enhanced by pre-incubation in calcium hopantenate. Ifenprodil tartrate inhibited K+-induced Ca2+ uptake in canine cerebral arteries and this was enhanced by pre-incubation in calcium hopantenate. These results suggest that the enhancement by calcium hopantenate of the ifenprodil tartrate effect on the vertebral blood flow is due to increased vascular relaxation through the inhibition of Ca2+ influx.

Animals↗
PubMed1988

Basic studies on the laboratory assessment of macrofilaricides using Brugia malayi in the jird, Meriones unguiculatus. 1. Longevity and periodicity of microfilaremia.

The longevity and periodicity of microfilaremia were examined in the jird infected with Brugia malayi to be used for assessing the filaricides. Jirds 4 to 6 weeks old were inoculated subcutaneously with 100 to 200 infective larvae of B. malayi. Microfilariae were present in 75 out of 94 jirds observed over 3 years and high microfilaremia, with 10 mf/microliters or higher, developed in 43 out of 75 jirds. Such a high level of microfilaremia was necessary for narrowing the variation of microfilaria counts among the blood samples. The microfilaria negative jirds, 4 months after inoculation, were abandoned, because in those cases where they became patent later the microfilaria density did not reach an appropriate level. The selected jirds were used for experiment from 6 to 15 months after inoculation when most of them revealed the maximal count of microfilariae. The jirds that failed to develop microfilaremia to the level of 10 mf/microliters by 9 months after inoculation were also abandoned because they did not continue the appropriate level of microfilaremia even when they reached this level later. Although a significant periodicity was observed only in of 10 jirds examined by the Aikat and Das method, the peak hour of microfilaria density was observed in most animals in the afternoon and the time was nearly the same in each animal. Therefore, the blood sampling would be performed preferably in the afternoon.

Animals↗
PubMed1988

Basic studies on the laboratory assessment of macrofilaricides using Brugia malayi in the jird, Meriones unguiculatus. 2. Establishment and evaluation of a new method of macrofilaricide assessment.

Jird infected subcutaneously with infective stage larvae (L3) of Brugia malayi were evaluated as an animal model for assessing macrofilaricides using a method of observing the change in microfilaria (mf) density but not by recovering adult worms. The animals were treated with a test compound followed by diethylcarbamazine (DEC) at 50 mg/kg for 5 consecutive days for clearing the existing mf from the blood stream. A continuous decrease in mf density was observed when jirds were treated with flubendazole. Nevertheless, slow recovery of mf density was observed in the jirds which were given suramin or Mel W, indicating that mf productivity of female worms was continuing after DEC treatment. The results obtained by monitoring microfilaremia corresponded with those obtained by recovery of adult worms at autopsy, suggesting that the system of L3-induced B. malayi jird model is useful for testing macrofilaricides.

Animals↗
PubMed1988

Effects of ifenprodil tartrate on vertebral, basilar and internal carotid arteries.

Changes in blood flow of vertebral and internal carotid arteries of rats after the administration of ifenprodil tartrate were measured using the transit-time ultrasonic volume flowmeter. Tension of isolated canine basilar and internal carotid arteries was also tested isometrically. Ifenprodil tartrate produced a sustained increase in both vertebral and internal carotid arterial blood flow of rat. The increase in blood flow was greater in vertebral than in internal carotid arteries. Papaverine hydrochloride transiently increased arterial blood flow in both the vertebral and internal carotid arteries to approximately the same extent. Ifenprodil tartrate induced dose-related relaxation in basilar and in internal carotid arteries contracted with K+ (50 mM), and its effects were greater in basilar than in internal carotid arteries, while relaxation induced by papaverine hydrochloride was about the same in both arteries. These results suggest that the significant increase of vertebral arterial blood flow induced by ifenprodil tartrate is due to the peculiarity of vascular myorelaxation by this drug.

Animals↗
PubMed1987

Effect of human recombinant granulocyte/macrophage colony-stimulating factor and native granulocyte colony-stimulating factor on clonogenic leukemic blast cells.

The effects of human recombinant granulocyte/macrophage colony-stimulating factor (GM-CSF) and human native purified granulocyte colony-stimulating factor (G-CSF) on the growth of clonogenic leukemic blast cells from eight Japanese patients with acute myeloblastic leukemia were studied, using an in vitro leukemic blast colony assay. The results showed that GM-CSF stimulated leukemic blast colony formation in all cases examined, whereas G-CSF stimulated colony formation in four of the eight cases. The maximum stimulating activity of GM-CSF on the growth of clonogenic leukemic blast cells was higher than that of G-CSF in the majority of cases, while sometimes GM-CSF and G-CSF worked synergistically. Thus, the clonogenic leukemic blast cell populations seemed to be heterogeneous with respect to their in vitro response to growth regulators.

Colony-Stimulating Factors↗
PubMed1987

Aging test and dynamic fatigue test of apatite-wollastonite-containing glass ceramics and dense hydroxyapatite.

The purpose of this study is to examine the changes in mechanical strength of two bioactive ceramics in living tissue. An aging test and dynamic fatigue test were performed using apatite-wollastonite-containing glass ceramics (A X W-GC) and dense hydroxyapatite (HA). Specimens (5 mm X 5 mm X 25 mm, abraded with No. 2000 Al2O3 powder) were implanted into subcutaneous tissue of rats for varying periods of time. The bending strength of aged samples was measured by the three-point loading method. The bending strength of A X W-GC was greater than that of HA (P less than 0.001). There was no reduction in bending strength for both A X W-GC and HA in living tissue. The n value of both A X W-GC and HA did not decrease significantly after implantation as assessed by the results of the dynamic fatigue test according to analysis of covariance. SEM-EPMA showed that Si and Mg contents decreased, Ca content did not change, while P content increased in the surface of A X W-GC. The area where x-ray intensity changed increased moderately after implantation. There were no changes in Ca and P at the interface between HA and soft tissue. In macroscopic and microscopic observations, specimens were found to be encapsulated with a thin layer of connective tissue. Foreign body giant cells, osteoblasts, or osteoclasts were not observed in the soft tissue. There was no bonding between ceramics and soft tissue.

Animals↗
PubMed1987

Bonding behavior between two bioactive ceramics in vivo.

The purpose of this study is to examine the chemical bonding mechanism between bioactive ceramics in vivo. Two experiments were performed. In the first experiment, rectangular specimens (5 mm X 5 mm X 25 mm) of apatite-wollastonite containing glass-ceramics (designated A.W-GC) were used. In the second experiment, plates (15 mm X 10 mm X 2 mm) of A.W-GC and three types of hydroxyapatite (designated HA) were used. The sintering temperature and porosity (%) of the three types of HA were 1200 degrees C (0.4%), 1000 degrees C (4.8%), and 800 degrees C (45%), respectively. In each experiment, two pairs of specimens of identical material, one bound with silk thread, the other not bound, were implanted subcutaneously into rats. In the first experiment, bonding of only bound specimens was observed at 3 and 6 months after implantation. The observation of interface by SEM-EPMA showed that a Ca-P-rich layer formed between the two specimens. In the second experiment, bonding of both bound and nonbound A.W-GC produced identical results 1 month after implantation. For HA sintered at 800 degrees C and 1000 degrees C, bonding was observed in every specimen. This phenomenon might be caused by the chemical change of hydroxyapatite occurring at different sintering temperatures. The Ca-P-rich layer was observed between two plates. These results suggest that self-repair of bioactive ceramic is possible under certain conditions.

Animals↗
PubMed1987

SEM-EPMA observation of three types of apatite-containing glass-ceramics implanted in bone: the variance of a Ca-P-rich layer.

The progressive changes of a Ca-P-rich layer between bone and three types of apatite-containing glass-ceramics of the same chemical composition: MgO 4.6, CaO 44.9, SiO2 34.2, P2O5 16.3, CaF2 0.5 (in weight ratio) were examined. Plates (15 mm X 10 mm X 2 mm, mirror surface) containing apatite (35 wt%) (designated A-GC), apatite (35 wt%) and wollastonite (40 wt%) (designated A.W-GC), and apatite (20 wt%), wollastonite (55 wt%), and whitlockite (15 wt%) (designated A.W.CP-GC) were prepared. They were implanted into the tibia of mature male rabbits for 5 days, 10 days, 20 days, 30 days, 60 days, 6 months, and 12 months. All three types of glass-ceramics showed direct bonding to the bone 30 days after implantation. It was observed by SEM-EPMA 30 days after implantation that Si and Mg content decreased, P content increased, and Ca content did not change across the reactive zone from the glass-ceramics to bone. The level of P and Si in the A.W.CP-GC changed five days after implantation. In A.W-GC and A-GC, a little change in P and Si levels was observed between 10 and 20 days after implantation. The width of reactive zone was narrowest with A-GC, wider with A.W-GC, and widest with A.W.CP-GC. The dissolution of glass-ceramics stopped 6 months after implantation. This phenomenon shows that the glass-ceramics may be suitable for clinical use.

Animals↗
PubMed1987

Synergism of leukemic blast growth factors in medium conditioned by human bladder carcinoma cell line 5637.

Leukemic blast growth factors (LBGFs) are necessary for in vitro growth of clonogenic cells from patients with acute myeloblastic leukemia. As the human bladder carcinoma cell line 5637 had previously been reported to secrete abundant LBGFs into the culture supernatant, the LBGFs in 5637-conditioned medium (5637-CM) were characterized. Measurement of LBGFs was done using an in vitro leukemic blast colony assay in methylcellulose culture. LBGFs in 5637-CM were fractionated by anion exchange chromatography, and two peaks of activity were recovered. Pool B (high-salt eluent) and/or purified granulocyte colony-stimulating factor (G-CSF) were added to the clonogenic leukemic blast cell assays. It was found that pool B was more active than G-CSF in the majority of cases examined and that the two types of activity were synergistic in some cases.

Cell Division↗